diff --git a/headers/private/libroot/locale/ICUCollateData.h b/headers/private/libroot/locale/ICUCollateData.h
index fd481f3f71..5d8e13eaee 100644
--- a/headers/private/libroot/locale/ICUCollateData.h
+++ b/headers/private/libroot/locale/ICUCollateData.h
@@ -28,8 +28,8 @@ public:
 	virtual	status_t			SetToPosix();
 
 			status_t			Strcoll(const char* a, const char* b, int& out);
-			status_t			Strxfrm(char* out, const char* in, size_t size,
-									size_t& outSize);
+			status_t			Strxfrm(char* out, const char* in,
+									size_t outSize, size_t& requiredSize);
 			status_t			Wcscoll(const wchar_t* a, const wchar_t* b,
 									int& out);
 			status_t			Wcsxfrm(wchar_t* out, const wchar_t* in,
diff --git a/headers/private/libroot/locale/ICULocaleBackend.h b/headers/private/libroot/locale/ICULocaleBackend.h
index 93e4d9f819..c8f034d3d5 100644
--- a/headers/private/libroot/locale/ICULocaleBackend.h
+++ b/headers/private/libroot/locale/ICULocaleBackend.h
@@ -59,8 +59,8 @@ public:
 	virtual	const char*			GetLanginfo(int index);
 
 	virtual	status_t			Strcoll(const char* a, const char* b, int& out);
-	virtual status_t			Strxfrm(char* out, const char* in, size_t size,
-									size_t& outSize);
+	virtual status_t			Strxfrm(char* out, const char* in,
+									size_t outSize, size_t& requiredSize);
 	virtual	status_t			Wcscoll(const wchar_t* a, const wchar_t* b,
 									int& out);
 	virtual status_t			Wcsxfrm(wchar_t* out, const wchar_t* in,
diff --git a/headers/private/libroot/locale/LocaleBackend.h b/headers/private/libroot/locale/LocaleBackend.h
index 5309595a98..272bbf77dc 100644
--- a/headers/private/libroot/locale/LocaleBackend.h
+++ b/headers/private/libroot/locale/LocaleBackend.h
@@ -167,8 +167,8 @@ public:
 
 	virtual	status_t			Strcoll(const char* a, const char* b,
 									int& out) = 0;
-	virtual status_t			Strxfrm(char* out, const char* in, size_t size,
-									size_t& outSize) = 0;
+	virtual status_t			Strxfrm(char* out, const char* in,
+									size_t outSize, size_t& requiredSize) = 0;
 	virtual	status_t			Wcscoll(const wchar_t* a, const wchar_t* b,
 									int& out) = 0;
 	virtual status_t			Wcsxfrm(wchar_t* out, const wchar_t* in,
diff --git a/src/system/libroot/add-ons/icu/ICUCollateData.cpp b/src/system/libroot/add-ons/icu/ICUCollateData.cpp
index ce3466a880..57b86b3a88 100644
--- a/src/system/libroot/add-ons/icu/ICUCollateData.cpp
+++ b/src/system/libroot/add-ons/icu/ICUCollateData.cpp
@@ -114,17 +114,18 @@ ICUCollateData::Strcoll(const char* a, const char* b, int& result)
 
 
 status_t
-ICUCollateData::Strxfrm(char* out, const char* in, size_t size, size_t& outSize)
+ICUCollateData::Strxfrm(char* out, const char* in,
+	size_t outSize, size_t& requiredSize)
 {
 	if (in == NULL) {
-		outSize = 0;
+		requiredSize = 0;
 		return B_OK;
 	}
 
 	if (fCollator == NULL || strcmp(fPosixLocaleName, "POSIX") == 0) {
 		// handle POSIX here as the collator ICU uses for that (english) is
 		// incompatible in too many ways
-		outSize = strlcpy(out, in, size);
+		requiredSize = strlcpy(out, in, outSize);
 		for (const char* inIter = in; *inIter != 0; ++inIter) {
 			if (*inIter < 0)
 				return B_BAD_VALUE;
@@ -136,7 +137,7 @@ ICUCollateData::Strxfrm(char* out, const char* in, size_t size, size_t& outSize)
 	if (_ToUnicodeString(in, unicodeIn) != B_OK)
 		return B_BAD_VALUE;
 
-	outSize = fCollator->getSortKey(unicodeIn, (uint8_t*)out, size);
+	requiredSize = fCollator->getSortKey(unicodeIn, (uint8_t*)out, outSize);
 
 	return B_OK;
 }
diff --git a/src/system/libroot/add-ons/icu/ICULocaleBackend.cpp b/src/system/libroot/add-ons/icu/ICULocaleBackend.cpp
index 5ce51a62d6..7c9657a496 100644
--- a/src/system/libroot/add-ons/icu/ICULocaleBackend.cpp
+++ b/src/system/libroot/add-ons/icu/ICULocaleBackend.cpp
@@ -296,12 +296,12 @@ ICULocaleBackend::Strcoll(const char* a, const char* b, int& result)
 
 
 status_t
-ICULocaleBackend::Strxfrm(char* out, const char* in, size_t size,
-	size_t& outSize)
+ICULocaleBackend::Strxfrm(char* out, const char* in,
+	size_t outSize, size_t& requiredSize)
 {
 	ErrnoMaintainer errnoMaintainer;
 
-	return fCollateData.Strxfrm(out, in, size, outSize);
+	return fCollateData.Strxfrm(out, in, outSize, requiredSize);
 }